Today, in motor vehicle systems, the function of inclination or tilt sensing is generally carried out using mercury switches. A ball of mercury is displaced from its rest position, under the influence of static gravitational acceleration, according to the inclination angle of the sensor. Upon passage beyond a defined angle, this displacement causes interruption of an electrical contact. For reasons of toxicity, the use of these mercury switches will be increasingly restricted in the years to come.
U.S. Pat. No. 4,955,234, MAREK/BOSCH, and corresponding German application P 38 14 952, disclose a micromechanical silicon acceleration sensor in which a pendulum, supported on one or more bending bars, is displaced from its rest position by a force acting perpendicular to the chip surface. The displacement is determined piezo-resistively by the bending of the bars. These sensors are advantageously employed as acceleration sensors.
German Patent DE-PS 36 25 411, SEIDEL, Nov. 11, 1988, assigned to the Messerschmidt-Bolkow-Blohm GmbH aerospace company, discloses a micromechanical acceleration sensor with capacitive signal pickup. With the aid of two fixed-position counterelectrodes, the displacement of a silicon mass, supported on multiple bars and serving as the middle electrode of a differential capacitor, is detected.
From German application P 39 27 163 and corresponding PCT/DE90/00596, it is known to etch out further structures from semiconductor wafers.